Along with Cycling I am also an avid Motorcyclist. I am not sure about Cycling helmets but Motorcycle helmets have a shelf life if you are entering any type of racing event. 5 years for most sanctioning bodies. I was told the reason for this has mostly to do with the foam. Over time the foam breaks down from sweat and compression from moving around on the head over the years. No as far as riding on the street my main helmet is about 7 years old now and the new equivalent of that helmet is over $500 so I keep rocking the old lid. I do have a couple newer helmets that I used when I was racing but the only reason I bought those was because of the age of my good old stand by. Not to mention I didn’t want to destroy my fav. helmet when I crashed.
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